The selection of one or more treatment modalities (e.g., radiation therapy, chemotherapy and surgery) has been empirically derived based on trials with these agents in previously treated patients. However, in the individual case one cannot predict whether or not that tumor will respond to treatment nor the extent of that response. As a consequence, individual patients may be subjected to a protracted course of therapy which ultimately may be ineffective or may be denied a potentially useful therapy because of the statistical likelihood that the tumor will not respond. It would be desirable to have a noninvasive in vivo system to predict whether an individual will respond to treatments and, therefore, optimize the course of therapy. Utilizing the newly implemented (1) in vivo magnetic resonance spectroscopy (MRS) on a 1.4T wholebody imager, we intend to characterize the alterations of phosphorous metabolites and intracellular pH of human neoplasms in response to radiotherapy and correlate the MRS findings with the clinical end points. In order to obtain a statistical significance of these studies, a large number of patient population with either squamous cell carcinoma or lymphoma (Hodgkin or nonHodgkin will participate in this project. The MRS data will be further correlated to the distribution of aneuploid and euploid populations obtained from the measurement of DNA content by flow cytometry. The MRI measurements will also be made to identify the boundary, inhomogeneity and central necrosis of tumors. Histopathological analysis will also be performed for each case. It is hoped that some of the biochemical processes and radiobiology of human neoplasms in response to the fractionated gammairradiation regimen will also be delineated. Ultimately it would be possible to predict whether the treatments will control the tumor base on the characteristic changes in the MRS spectra, and one may more rationally choose the primary modality and decide the need for one or more adjuvant therapies (e.g., surgery, chemotherapy, etc.)